Because of the recent trend toward micronization of manufacturing technology, accompanying higher density of integrating, and multiplication of numbers of terminals of an integrated circuit, there are increasing requirements on improvements of technologies on bonding an integrated circuit with multi-terminals to a substrate of complicated electronic circuits.
Among various methods for bonding integrated circuits to substrates of electronic circuits, wire-bonding, TAB and flip-chip methods are well known. However, for implementation of integrated circuits with multi-terminals, flip-chip method is the most suitable, because in this method, terminals for bonding can be provided at will all over surfaces of integrated circuits, and therefore number of terminals can be easily increased. Moreover, lengths of wirings can be shortened, hence excellent electrical performances. As compared with flip-chip method, in wire-bonding and TAB methods, terminals for bonding must be provided only around outer peripheries of integrated circuits.
Accordingly, within the past ten years or so, flip-chip method has been investigated or used on trial as promising implementations for large scale electronic computer, and its applications to liquid crystal display devices are being studied at present.
In a case of flip-chip bonding, hitherto, estimation on electrical performances of an integrated circuit is carried out, after bonding is completed. Accordingly, when defects of an integrated circuit are found, demounting of an integrated circuit and reclamation of a substrate, to which an integrated circuit has been fixed, are very difficult.
These problems are originated from the fact that it is very difficult to carry out sufficient estimation on electrical performances of an integrated circuit at a chip state before flip-chip bonding.
To overcome these difficulties, a sheet formed connector, which connects terminals of an integrated circuit and those of a substrate for inspection, was invented and disclosed on Japanese Patent Kokai No. 60-100441. This connector is consisted of an insulating plastic sheet, in which many fine wire pieces are buried. All of these fine wires are perpendicular to the surface of the sheet, and arranged at a predetermined interval in both longitudinal and lateral directions of the sheet.
The sheet formed connector is inserted between the integrated circuit to be inspected and the substrate for inspection, and pressed from both sides, and thereby required electrical conductions are made between aforementioned two circuits.
But, the pressure necessary for the inspections is large, and there are fears of damages of the integrated circuit and the substrate for inspection.